The middle and largest part of the book — 100 pages or so — is the most interesting and useful. The author attempts, with some success, to acquaint the nonspecialist reader with mainstream philosophical views of the nature of science. As one would expect, the discussion centers on the works of philosophers of science Karl Popper, Thomas Kuhn, Imre Lakatos, Paul Feyerabend, and Richard Rorty; by far the heaviest emphasis is placed on Kuhn's analysis of scientific revolutions (Kuhn 1996). Inevitably, as the author warns the reader, the discussion cannot be complete — only so much can be conveyed in a relatively brief summary.
"Truth", the key word in the title, is a slippery term. In theology, it has at least one clear meaning: What is revealed in sacred scriptures is by definition true, and theological argument can proceed on this sound foundation — at least among those theologians who share faith in that particular revelation. Science, however, does not have such a starting point. Popper stressed the now widely accepted view that science can never achieve truth but it can make and then test assertions that are falsifiable. If a theory survives numerous and varied attempts at falsification, one can have a degree of confidence in the reliability of that theory over a broad range of phenomena. Moreover, if a statement is inherently not falsifiable (for example, "God is just"), it cannot be a scientific statement.
If a scientific theory cannot be "true", can it at least be "correct"? Certainly, in the sense that it accounts for a range of phenomena with good accuracy and can be used to predict the outcome of previously unknown events. Scientists, in contrast to philosophers of science, do not worry too much about this point. Given a particular problem, it is usually pretty obvious to the skilled investigator which theory will yield a satisfactory solution.
How are the sciences related? Singham argues that most scientists are reductionists. Perhaps he is led to this view in part by the hyperbolic titles that famous particle physicists give to their writings aimed at a broader public — and particle physicists do love to use such names as "The Theory of Everything" to describe their work, sometimes only partly facetiously (Lederman and Teresi 1993; Weinberg 1994). If Singham were to consider the views of scientists other than his fellow particle physicists, he might well take a different position regarding the philosophical stance of most scientists. Moreover, the reductionist position he frames is idiosyncratic; he argues that physics deals with the smallest objects (subatomic entities), chemistry with larger molecules, and biology with large chemical systems. He therefore sets up a reductionist hierarchy that is strictly one of scale. He continues,
the smaller the size scale of the discipline, the closer to truth that discipline is judged to be. Thus, a complete understanding of particle physics would explain how protons, neutrons, and other nuclear particles are formed and how they interact to form nuclei. Since these form the constituents of nuclear physics, all of nuclear physics also would be explained. Similarly, once we know how atomic nuclei form and interact with other atomic components, we would have explained atomic physics and chemistry. … And once we have completely explained chemistry, then we also will have explained biology, then upward through the latter to society and the universe.This is, I think, a straw-man description of reductionist epistemology too naïve to convince most scientists. It founders immediately on the rocks of emergent properties. There can be no doubt, for instance, that biological systems obey the rules of chemistry without exception. But the rules of chemistry could never have predicted a priori that genetic information is carried by DNA, or that the bases A, C, G, and T comprise the alphabet that conveys that information as it does. Similarly, a thorough knowledge of a deer as a biological organism will not furnish a basis for explanation of the complex herd behavior of the species to which it belongs.
Later, Singham digresses into a cogent and, I think, widely accepted criticism of the way science is taught at all levels below graduate school. He adopts the so-called constructivist view of education — the instructor should not simply assume that his students' preconceptions are wrong and then proceed to lecture them on the correct stuff, but should let them build on their own knowledge systems and arrive at the consensus of modern science through a process of adding new experience to what they already know. While I am sympathetic with this approach as a pedagogic technique, I do not see it as a basis for a philosophy of science. Moreover, I am not at all clear as to what the discussion of constructivist pedagogy contributes to the main argument of the book, except that it leads by inference to the view that pseudoscience has intrinsic intellectual value.
Singham finally comes to what I take to be his solution to the problems of public misconceptions of science and the conflict between science and religion. This solution lies in acceptance of the ideas that (a) all knowledge is valid and (b) science does not seek truth but control over the environment. In adopting this position, Singham comes close to abandoning the distinction between science and pseudoscience. As a corollary, he argues that the important court decisions that distinguish between creationism and science are not intellectually honest. Most scientists would maintain that, complex philosophical structures aside, it is not too difficult to distinguish between science and pseudoscience on the basis of straightforward criteria. In the same way, several courts have not found much difficulty in distinguishing between real science and religiously based programs disguised as science.
Singham further reconciles the Kuhnian concept of incommensurable paradigms (for example, Newtonian physics vis-à-vis quantum mechanics) by making an analogy with biological evolution. Just as species branch from pre-existing species — the metaphor is that of a proliferating shrub — new theories branch from pre-existing ones. In both cases, the process is contingent; if the pre-existing branching structure had been different, the new branching would have been, too. Singham argues further that this metaphor avoids the misconception that knowledge — at least, scientific knowledge — is finite and we will someday know everything there is to know about the universe. Rather, Singham's shrub branches out unendingly into the spaces available between and above the existing branches.
This metaphor is a pretty one and may satisfy many readers. My own view is that it is not very useful except for convincing those who are too much influenced by the idea of a Theory of Everything.
It is, I think unfortunately, never terribly clear how all this will solve the problem of widespread public belief in creationism and other pseudosciences. Nevertheless, the book is a good read and a good way for the educated but nonspecialized reader to approach both the current problems of the philosophy of science and its position in the scientific world.